WAS Protein Family Homolog 1 (WASH1)

WASH has 2 WASH homology domains (WHD1 and WHD2) in its N-terminal half. In its C-terminal half, WASH has a proline-rich stretch followed by a WH2 actin-binding domain (V), a central region (C), and an acidic stretch (A) that together form the VCA module found in all WASP proteins. The VCA module mediates binding to actin and the ARP2/3 protein complex and stimulates actin nucleation. Northern blot analysis detected an approximately 1.8-kb transcript in all tissues examined. RNA dot blot analysis and RT-PCR confirmed ubiquitous and variable WASH1 expression. Database analysis revealed WASH orthologs in both vertebrates and invertebrates. Vertebrates showed highest conservation in the WASH C terminus. Fluorescence-tagged WASH1 colocalized with cytoskeletal actin and accumulated in filopodia and lamellipodia.